Due to its lighter weight and better crack resistance compared with an inorganic lens, a plastic lens is rapidly being distributed as an optical element such as an eyeglasses lens or a camera lens. In recent years, development of a plastic lens having photochromic performance has been in progress.
Examples of the above-described plastic lens include techniques described in Patent Documents 1 to 4.
Patent Document 1 describes a lens comprised of a composition including a predetermined photochromic compound and a di(meth)acrylate compound. Paragraph [0009] describes that, in a case in which a urethane resin or a thiourethane resin having a high refractive index is used, isocyanate that is a raw material of the resin reacts with the photochromic compound in a monomer phase, and the photochromic performance is no longer exhibited.
Patent Document 2 discloses a lens in which a coating layer comprised of a composition including a photochromic compound having a chromene skeleton and a phenol compound is provided on the surface of a thiourethane-based plastic lens.
Patent Document 3 discloses a photochromic lens including a lens base material comprised of a thiourethane resin and a photochromic film formed by applying a solution including a photochromic compound and a radical polymerizable monomer onto the base material.
Meanwhile, Patent Document 4 discloses a compound having photochromic characteristics.